Bird feeder base



FIG. 1 is an upper perspective view of a bird feeder base showing the new design;

FIG. 2 is a lower perspective view of the bird feeder base;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof; and,

FIG. 5 is a side view thereof, where the front view, opposite side view and back view are identical to the side view in FIG. 5 .

The broken lines showing portions of the bird feeder base form no part of the claimed design. 

CLAIM The ornamental design for a bird feeder base, as shown and described. 